Lift-bridge.



B. SWENSSON: LIFT BRIDGE.

v APPLIOATION PIVLYED DEO- 9, 1907. Patented Feb' 9,

4 SHEETS-SHEET 2.

Hmm/raf? A7V/fA .Smm/550% y E. SWENSSON.

, LIFT BRIDGE. APPLIOATION FILED DBo.9,19o7.

Patented Feh.'9,ll909.

4' SHEETS-SHEET 3.

E. SWBNSSON.

LIFT BRIDGE. APPLICATION FILED DEO. 9,1907.

Patented Feb.4 9, 1909.

4 SHEETS-SHEET 4.

lflll/fl L UNMSM ,54; Mai/vers Enric swENssoN, or MINNEAPOLIS,MINNESOTA.

- LIFT-BRIDGE.

. Specification of Letters Jiatent.

Patented Feb.` 9, 1909.

. Application IedDGcember 9, 1907. Serial No. 495,697. N l

To all 'whom it. may concern: y v

Be it known that I, ERIC SwENssoN, of Minneapolia Hennepin' county,Minnesota, have invented certain new and useful Improveniente inLift-Bridges, of Which the llowing is a specification.

f The object of my invention is to provide 1.a lift bridge to'take theplace of an ordinary draw or swing bridge, a lift bridge in itsfundamental urposeI and uses similar to other lift bri ges alreadyconstructed and in operation, but of a new type vastly more simple andeconomical.

rLong experience has shown that lack oi room and many .otherdifficulties impossible to specify' herein, with types of lift bridgesso far constructed, leadto complicated,

troublesome and expensive designs. This is avoided by using myinvention, the.

gyratory llift bridge, the designs Jfor thisy type of bridge in allcases becoming exceedingly simple and economical.

My invention consists generally in a l bridgespan of any ordinary typeand having i trunnions, which rest on and are anchored in two.stationary towers, one at each end a suitable roadway, this bridge,span being.

at each end, by means of vertical arms of proper construction, suspendedon` two .of the' bridge. Thus, by -means oi suitable machinery I swingthe entire bridge span around ia horizontal, longitudinal axis lso thatwhen the bridge is open, the movable bridge span occupies a raised,.inverted position, with sufiicient clearance above the water level to'allow the largest vessels to pass beneath the inverted span. To reducethe power necessary 'for moving tl e bridge, to an absolute minimum, Iprovide countervweights so that the movable part the bridge is perfectlyvbalanced around the center line of the trunnions. i

Further,.the invention consists in .various /constructions andcombinations, altas .hercinaiter fdescribe'd and particularly pointedout in the claims.

In the accompanyingdrawings, forming part of this specilication, Figurelis a side elevation partially in section, of a gyratory lift bridgeembodying my invention and View illustrating the movable span Iswung toits inverted position to admitfiree passage of the largest vessels. Fig.3 is a vertical portion of the operating mechanism, viz: ,f

the circular rack and the corresponding operating pinion. Fig. 5 is asectional view illustrating thewedges for transferring the load to theabutment. Fig. 6 is a detail View taken on the line substantially atright angles to the section line oi Fig. 5. Fig. 7 is a detail view'ofthe gear mechanism for operating the wedges. Fig. 8 is a detail viewillustrating a means for locking the bridge. l

-My invention consists, generally speaking, ina bridge span havingvtrusses or plategirders as main carriers and a floor construction forthe roadway, suitable for the .demandsl of any particular case, and notdiffering materially from well-known modes of bridge construction. Thespan, .I will indicate by reference numeral 2, Aand the roadway bynumeral 3.

4 re'resents the abutments atl each end of the ridge.

Instead of resting the span 2.directly. upon the abutments as is usualin fixed bridges I. provide two su-spensory frames 5 of suitableconstruction, one at each end oithe spanand Isuspend these .frames intrunnions 6 which are anchored or supported .in upright towers 7. Theframes 5 and the iixed towers are portal formed so as to admit theroadway and give necessary clearance for same. The frames 5 may turn onthe-trunnions secured in the towers or the trunnions may. be secured inthe frames and jo'urnaled in the towers. These towers thus carry throughthe trunnions, the entire dead load of the span.

,Heavy steel castings 8 su port the trunniilsin the towers and thebearing surfaces of tirotrunnions in the frames 5, are suitablycushioned. jIn the upper parts of the frames 5 I provide counter weights9'oi suitable material and arranged to act as lcounter balances for theentire lower portionol the span. These Weights are' so adjusted that theentire moving bridge is perfectly balanced around the centerline of thetrunnions. 'lliis balancing ol' the bridge wi-llbe so perfect that onlysullicient power to overcome Wind .pressure-and friction will benecessary to open or close thebrdge.

T U 1 l bil(r I 1`ll" l() o operate t ie m zwe, prox 1( c rac \s' lclrcular' 1n form and arranged to mesh wlth operatlng pnnons 11 winchare connected through a suitable reduction gearing 12 with motors 13 orother suitab.e prime movers. I

.have illustrated the mechanism l'or operating the bridge at one end eny, but it will be un derstood that a similar apparatus is generallyprovided at. theppposite end. lhe motor and thegear mechanism isarranged within a suitabe inclosure 14 which may form thebridge-operators dwening. Suitable l'riction ra have not thoughtnecessary to illustrate, are provided in connection with the gearing 12and., the attendant can by means et' this gearing and brake mechanism,open and close the bridge easiy and quickly.

Itor a small bridge an operating mechanism,at one end on.y may beprovided, while for larger structures a similar apparatus is preferablyprovided at each end.

For small boats which do not require much clearance, I may raise thebridge only 'a short distance, while lor the larger boats the span maybe swung to a completely inverted position. Also, 'depending on the sizeof vesse.s required to pass under a given bridge, may placethe trunnionsor towers oil suitable height. InA this way, the invention can beadapted to any given condition of tratiic.

Under the ends of the main carriers I provide wedges or other suitabledevices for the purpose of transferring, when the bridge is elosed,'alllive load-directly from the bridge span down to the abutment, insteadof,

transmitting it through the frames .5 and the trunnions and then throughthe upright towers to ,the abutments. l

16 represents the wedges having dovetail recesses 1,7 therein to titcorrespondingly sha ed seats on the abutments. 'l'hese We ges aremounted onrods 18 having right and left hand threads in a hub 19 that isprovided with a beveled gear 20. A similar gear 21 meshes with the gear20 and is secured on a shaft 22. A gear 23 is mounted on said shaft andmeshes with a pinion 24 on the shalt of an operating motor 25. By meansof this mechanism the wedges are moved back and forth for the purpose olsupporting` the bridge directly upon the abutments and transmitting thelive load thereto instead of allowing the load to'be transmitted throughthe frames 5 to the trunnions and towers. For the purpose oll lockingthe bridge I provide a plate 26 having a socket 27 to receive a bolt 28on the armature 29 of a solenoid 3Q. The current being applied to thissolenoid its armature will be withdrawn and the bolt disengaged from thesocket to release the bridge.

I'do not Wish to be conned to the structural frame of this bridge or tothe mechanisrnyshown for operating it, as both may be modified invarious ways to Suit dilierent conditions. Various means may also be esol' ordinary construction which'` employed for transmitting the liveload to the abutments and preventing the bridge from swinging under windpressure.

I claim as my invention :4-

1, A bridge of the class describedcomprising a span having a road-wayand towers having portals forming eontinuations of said road-way onwhich towers the said span is journaled, counter weights for said spanand means for swinging said span laterally to an inverted position toopen the bridge.

2. A hlt bridge comprising a span' pro vided with a roadway and havingtrames at each end with portals theretln'ough, and

towers having portals, trunnions supporting said trames on said towers,counter balance weights mounted on saidi'rames above said trunnions andmeans l'or swinging said span to an inverted position.

3. A bridge oi the class described, comprising a span having a roadway,frames at each end ot' said s nm provided with portals and towers alsohaving portals, trunnions supporting said frames` on said towers,counterlbalance' weights. carried by said frames and means for wedgingsaid span to transfer the live load to the abutments and resist windpressure, substantially aarde scribed.

4. A bridge of the class described com- 1' rising'ra span having a'road-way, towers raving ortals leading to said road-way and on whicitowers the said span is journaled and means for swinging said span onits axis to an inverted position'to open the l idge "5. A bridge of theclass described, comprising a movable span with suspcnsory trames ateach end oll the same, and lixcd towers at each end ol the bridge,whereon said span is suspended and journaled, and means l'or swingingsaid span around a horizontal, longitudinal axis to an open invertedposition, substantially as described.

6. A bridge of the class described, comprising a movable span with sus)ensory frames at each end ol same, and fixe towers at each end of thebridge, whereon said span is suspended and journaled, counter-balanceweights to balance said movable span around the center line ci thejournals or trunnions, and means for swinging said span sidewise aroundthe said center line to an open, inverted position, substantially asdescribed.

7. A lift bridge, comprising a movable span provided with a roadway andwith portal formed sus ensory frames at each end of said span, an( IwithliXed, portal-formed towers at each end, trunnions sup )orting saidframes on said towers, counter alance weights mounted on said framesabove said trunnions, and means for swinging said span around the axisof said trunnions to an open inverted position, substantially asdescribed. v 8. A bridge of the class described, com

Wind pressure, substantially as described.

my hand this 29th -oleyof October 1907.

ERIC SWENSSON. [L. s]

Witnesses ALFR. CARLssoN, LOUIS SAGERSTACK.

ments, and means forlooking said span to the abutments or iixed towers,thus preventing the bridge from unduly opening under In witness whereof;I have hereunto 'set

